5,6,7,8-tetrahydro-2,5(and 4,5)-dioxo-1-benzopyrans

ABSTRACT

COMPOUNDS OF THE FORMULA:   2,3-(-X-O-),R,R2-CYCLOHEX-2-EN-1-ONE   IN WHICH X IS THE MOIETY   -CO-C(-R3)=C(-CO-Z)-   Z IS A MEMBER SELECTED FOR THE GROUP CONSISTING OF   -OR4, -N(-R5)-R6   -CL,-BR, AND -OM; R, R2, R3, AND R5 ARE INDEPENDENTLY SELECTED FROM THE GROUP CONSISTING OF -H, LOWER ALKYL, PHENYL AND BENZYL, R6 IS SELECTED FROM THE GEOUP CONSISTING OF -H, LOWER ALKYL, PHEMYL, BENZYL, LOWER DIALKYLAMINOALKYL AND CYCLOALKYL OF 3 TO 10 CARBON ATOMS, AND WHEN TAKEN WITH R5 AND THE NITROGEN ATOM TO WHICH THEY ARE BONDED FORMS THE MORPHOLINO, PIPERIDINO AND PIPERAZINO GROUPS, AND M IS SELECTED FROM ALKALI METAL CATION AND -NH4, ARE IMMUNO-INFLAMMATORY AGENTS POSSESSING ANTIALLERGIC AND ANTIINFLAMMATORY ACTIVITY. THE COMPOUNDS OF THSI INVENTION ARE ALSO INTERMEDIATES FOR THE SYNTHESIS OF KNOWN CHROMONE AND COUMARIN DERIVATIVES.

fume odors, and as a masking flavor.

United States Patent Us. or. 260-343.: R 6 Claims ABSTRACT OF THE DISCLOSURE Compounds of the formula:

in which X is the moiety o R 0oz Z is a member selected from the group consisting of R, R R R and R are independently selected from the group consisting of H, lower alkyl, phenyl and benzyl,

R is selected from the group consisting of H, lower alkyl, phenyl, benzyl, lower dialkylaminoalkyl and cycloalkyl of 3 to .10 carbon atoms, and when taken with R and the nitrogen atom to which they are bonded forms the morpholino, piperidino and piperazino groups, and

M is selected from alkali metal cations and -NH are immuno-inflarnmator'y agentspossessing antiallergic and antiinflammatory activity. The compounds of this invention are also intermediates for the synthesis of known chromone and coumarin derivatives.

Aug. 26, 1971, by John H. Sellstedt, Stanley C. Bell and Ronald I. McCaully, now US. Pat. 3,775,435.

BACKGROUND OF THE INVENTION Chrome derivatives are known to present antiallergic activity (US. 3,484,445) while coumarin and its derivatives have been used extensively in the prior art as per- BRIEF DESCRIPTION OF THE INVENTION K This invention involves new chemical compounds of the dihydrocoumarin and dihydrochromone series which are useful as intermediates in the synthesis of chromone and conmarin derivatives and as immune-inflammatory agents.

3,823,164 Patented July 9, 1974 In accordance with this inveniton there are provided compounds of the formula:

in which X is the moiety O R. COZ

from the standpoint of availability of precursors and process economies are:

in which X is 0 R COY Z is a member selected from the group consisting of s OR', N

--C1 and OM; R, R R R R and R are independently selected from the group consisting of H and lower alkyl; and M'is selected from the group consisting of alkali metal and ammonium cations.

The substituents R and R may appear in any of the three available ring positions of the cyclohexanone ring on one or two carbon atoms. By lower alkyl, applicants intend to embrace alkyl groups containing from one to nine carbon atoms, such as the methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl and nonyl radicals all well as their branched chain analogues. The expression lower dialkylaminoalk'yl is intended to embrace the lower 'alkylgroups both in terms of nitrogen substituents and the amino substituted alkyl group.

i The 5,6,7,8 tetrahydro 2,5 dioxo-l-benzopyran derivatives-of-this-invention are produced by theiollowing gen-=-'-' eral reaction scheme:

where R, R R R, R and R have the structure given above. a V

U Similarly, the 5,6,7-tetrahydro-4,S-dioxo-l-benaopyran derivatives. may be prepared by a modified Kost'aneck- Robinson reaction as follows:

in which the RR groups have the character given supra.

In the preceding equations, the conversion of the free carboxylic acid to the amide is depicted to progress through the acid chloride. However, any acid activating agent may be employed to provide an intermediate for reaction with an amine in the preparation of the desired amide. For example, acid activating agents such as iso- ;butylchloroformate, carbonyldiimidazole, dicyclohexylcarbodiimide, etc. provide intermediates by reaction with the to produce the desired activated carboxylic acid inter- The 5,6,7,8-tetrahydro-2,5(and 4,5)-dioxo-1-benzopyran derivatives of this invention may be converted to known compounds of the chromone and coumarin series by known ring dehydrogenation techniques. In addition, the '5,6,' 7,8-"tetrahydro-2,5 (and 4,5 )-dioxo 1-beuzopyran derivatives of this invention exhibit iinmuno-inflammatory activity and are useful asanti-allerg'ic and" anti-inflam matory agents. In that sense, the compounds of this invention inhibit the release arid/oraction of toxic products that arise from the combination of certain types or specific antigenaantibody' reactions. Thus, the compounds of this invention may be'directly formulated into pharmaceutical compositions comprising. the hydrobenzopyran and a physiologically acceptable carrier or"diluent. Depending upon the type of administration desired, i.e. oral, parenteral or'inhalation, the. carrier or diluent for the compounds of this invention are tailored. Thus, the carrier may be liquid, solid or 'a vapor appearing in major proportion, such as water, propellants such as chlorotrifiuoroethane and dichlorodifluoroethane, and solid powders such as lactose, witha minor elfective amount of the active ingredient. Generally, from about 0.05 up to about 10 percent weight/weight ratios of the hydrobenzopyran to diluent are suitable although a larger or smaller amount of the active ingredient may be used.

The following specific examples are presented for purposes of illustration and are not to be construed as limit'a tions upon the true scope of the invention.

5,5-Dimethyl-1,3-cyclohexanedione (14.0 g., 0.1 mole) and sodium diethyl oxalacetate (21.0 g., 0.1 mole)--are refluxed intrifiuor'ozicetic'acid (50 ml.) for- 4 hours and the resulting mixture is kept at room temperature overnight. Most of the solvent is removed in vacuo at C. and the residue is poured into an ether-water mixture. The ether fraction was washed consecutively with water-,saturated aqueous sodium bicarbonate until basic, cold 0.5N NaOH, dilute acid,=water'andbrine. The ethereal solution is thendried withmagnesinm sulfate andconcentrated in vacuo, giving a white solid (7.4 g., 28 percent of theory) exhibiting amelting point of 133-137 C. (uncorrected). The solid is crystallized from ethyl acetate (30 ml.).-hex- 1 ane (45 ml.), giving 5.6 grams of white crystals exhibiting .carboxylic acid whichare easily reacted with an amine to aiford the desired amide. Furthermore, it is to be understood that any halogenating agent capable of converting the carboxylic acid to a carboxylic acid halide may be employed instead of the SOC1 or PC1 actuallypresented in .the equation. For example, various carboxylic acid halides, sulfuryl-halides, PCl PB1'3,.ctc. may be employed a melting pointof 136l38 C. (uncorrected); UV max.

(95 percent ethanol) 263 m (e 11,400), 296 my. center of plateau (6 6,530).

Analysis.Calcd for C14H1GO5Z C, H, 6-10.

Found: C, 63.59;'H,'6.01. a

The product was ethyl 5,6,7,8-tetrahydro-7,7 dimethyl- 2,5-dioxo-2. I- I 1-benzopyran-4-carboxylate.

I Example 2 5,6,7,8 Tetrahydro-7,7-dimethyl-2,5-dioxo-2g-1- benzopyran-4-carboxylic acid and salts The ethyl ester product of Example 1 (10.0 g.,'0.038 mole) is refluxed in 100 ml. of 1:1 dioxane-20 percent aqueous hydrochloric acid for about 6 hours. After storing at room temperature overnight, 8.0g. of a white' solid, melting point 218-223 C...decomposition (uncorrected) is recovered. The solid is crystallized from absolute ethanol, giving 6.4 g. white crystals: m.p. 2 22-224 C. (decomposition); UV maximum percent ethanol) my. (6 11,100), 296 my. inflection (6 6,240).

Analyis.Calc'd for CHI-11205: C," H; 5.12. Found: C, 60.78; H, 5.35.

The sodium salt is prepared by dissolving 2.1 g. of the free acid in boiling absolute ethanol (75 ml.), filtering, and adding 3.3 ml. of a 2.74 molar l-butanol solution of sodium 2-ethylhexanoate. A white solid (1.3 g.) is filtered off and dried in vacuo. The product exhibited a melting point over 300 C.; UV maximum in 95 percent ethanol of 264 my. (6 9,940), 293 m inflection (6 5,750).

Analysis.-Calcd. for C H NaO C, 55.82; H, 4.30. Found: C, 55.82; H, 4.40.

The ammonium salt is produced from the free acid by reaction with ammonia or ammonium hydroxidesolution.

EXAMPLE 3 5 ,6,7,8-Tetrahydro-N,N7,7-tetramethyl-2,5 dioxo- 2g-benzopyran-4-carboxamide 5,6,7,8-Tetrahydro 7,7 dimethyl 2,5 dioxo-ZE-lbenzopyran-4-carboxylic acid (23.6 g., 0.1 mol) and thionyl chloride (7.9 ml., 0.11 mol) are refluxed in benzene (300 ml.) until evolution of hydrogen chloride ceases. The solution is concentrated in vacuo and the residue is dissolved in dichloromethane 100 ml.). A solution of dimethylamine (9 g., 0.2 mol) in dichloromethane (50 ml.) is added to the acid chloride solution at 0-l0 C., and the mixture is stirred for about 4 hours. The solution is washed with water, sodium bicarbonate solution, brine, dried, and concentrated in vacuo, giving the title compound.

EXAMPLE 4 5,6,7,8-Tetrahydro-7,7-dimethyl-4,5-dioxo-4I -1- benzopyran-Z-carboxylic acid ethyl ester Absolute ethanol (10.25 ml., 0.175 mol) is added to a mixture of 50 percent sodium hydride (6.24 g., 0.13 mol) in 250 ml. of toluene. A solution of 2-acetyl-5,5- dimethyl-1,3-cyclohexanedi0ne (9.11 g., 0.05 mol) in diethyl oxalate (34 ml., 0.25 mol) is added to the toluene mixture at 10-20 C. over 20 minutes. The resulting mixture is stirred at 50 C. for about 3 hours, poured into 500 ml. of ice water, and the aqueous solution is washed twice with ether. The aqueous phase at 0l0 C. is acidified to pH 1 with concentrated hydrochloric acid in the presence of ether. The aqueous layer is extracted two more times with ether. The ether is washed with brine, dried with MgSO and concentrated in vacuo, giving 16.1 g. of an amber oil. The oil is chromatographed on 160 g. of Florex AA-RVM 60/90 mesh in benzene. Two 500 ml. fractions of benzene followed by two 500 ml. fractions of chloroform are collected. The first chloroform fraction is concentrated, giving 1.5 g. (11 percent yield) of a white solid, m.p. 128-132 C., which is crystallized from a mixture of ethyl acetate and hexane; m.p. 134-137 C.; UV max. (95 percent EtOH) 221 mp (e 22,800), 248 m (6 7,210).

Analysis.Calcd. for CHI-L505: C, H, 6.10. Found: C, 63.56; H, 6.05.

Concentration of the first benzene fraction gave 8.0 g. of a light yellow solid, m.p. 48-90 C. The solid is dissolved in 50 ml. of absolute ethanol, 3 ml. of ethanol saturated with gaseous hydrogen chloride is added, and the solution is refluxed for 20 min. After cooling in ice an additional 3.5 g. of light pink crystals of the title compound, m.p. 130-l36 C., were collected.

EXAMPLE 5 5,6,7,8-Tetrahydro 7,7-dimethyl-4,5-dioxo-4 11-1- benzopyran-Z-carboxylic acid and sodium salt 6 added, andmixture cooled to 0-5 and filtered giving 11.7 g. of a white solid. Crystallization from acetonitrile gives 8.7 g. (47 percent) of white crystals: m.p. 210-212 C. dec.; UV max. percent EtOH) 217.5 mp. (6 24,800), 247 me (e 8,830).

Anulysis.-Calcd. for c H O C, 61.01; H, 5.12. Found: C, 60.97; H, 5.12.

To a boiling, filtered solution of 2.64 g. (0.010 mol) of 5,6,7,8-tetrahydro 7,7 dimethyl-4,5-dioxo-4g-l-benzopyran-2wcarboxylic acid ethyl ester in 50 ml. absolute ethanol isaddcd with stirring 1.9 ml. of 5.25 N sodium hydroxide over 1 min. Crystals formed rapidly. and the mixture is kept on a steam bath for 10 minutes, cooled in ice, and filtered giving 1.7 g. (68 percent) of the salt as light buff crystals: m.p. over 300; UV max. 95 percent ethanol (e 27,900), 247 my (2 9,840).

Analysis.--Calcd. for C H NaO C, 55.82; Found: C, 55.65; H, 4.45.

EXAMPLE 6 5,6,7,8-Tetrahydro 7,7 dimethyl 4,5 dioxo-4g-1- benzopyran-2-carboxylic acid (23.6 g., 0.1 mol) and thionyl chloride (7.9 ml. 0.11 mol) are refluxed in benzene (300 ml.) until evolution of hydrogen chloride ceases. The solution is concentrated in vacuo and the residue is dissolved in dichloromethane ml.). A solution of dimethylamine (9 g., 0.2 mol) in dichloromethane (50 ml.) is added to the acid chloride solution at 010 C. and the mixture is stirred for about 4 hours. The solution is washed, sequentially with water, sodium bicarbonate solution and brine and is dried with MgSO, and concentrated in vaczgo, giving the title compound.

What is claimed is:

1. A compound of the formula:

in which Z is a member selected from the group consisting of RI N/ C1 and OH; R, R R R and R are independently selected from the group consisting of H and lower alkyl; and M is selected from the group consisting of alkali metal and ammonium cations. 2. The compound of Claim 1 of the formula:

(H) CO CgH;

7 v 8 4. The compound of Claim 1 of the formula 6. The compound 0 CON v 0 mo 0 v CH3 0 References Cited 5. The compound of Claim 1 of the formula: 1 0 UNITED STATES PATENTS 3,558,658 1/1971 McIntyre 260343.2 0 come JOHN M. FORD, Primary Examiner v 15 U.S. c1. X.R. 260-345.2;424---283 

